Headlight



U. WINSTON.

HEADLIGHT.

APPLICATION man AUG.2 1916.

1,345,056. L Patented June 1920.

3 SHEETS- T l.

O. WINSTON.

HEADLIGHT.

APPLICATION HLED A1161, I916.

Patented June 29, 1920.

3 SHEETS-SHEET 2 I b 9- y7 yn a IQIO C/Q; 0/) t a) 6/6 ATTOEN QQ O. WINSTON.

HEADLIGHT.

APPLICATION FILED AUGIZ, IQIG. 1,345,056 Patented June 29, 1920.

3 SHEETS SHEF 3 Fig.6

g g 2 @WM flaw ia/k/a OVERTON WINSTON, 0F MINNEAPOLIS, MINNESOTA.

HEAD LIGHT.

Specification of Letters Patent.

Patented June 29, 1920.

Application filed August 2, 1916. Serial No. 112,683.

To all whom it may concern:

Be it known that I, OVERTUN lVINS'ioN, a citizen ,of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Head lights; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appcrtains to make and use. the same.

My invention relates to headlights, such as used on automobiles, and elsewhere, to give an approximately.horizontal or forward projection of the light beam, and has for its object to materially improve the proportionate distribution of the light on and above the road.

In th'eaccompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.

Refcfi'ing to thedrawings;

Figure l is a front elevation showing the improved reflector;

Figs. 2, 3 and 4 are sections taken respectively on the lines 2+2, 3-3 and 4-4 of Fig. 1, and showing also a two-filament light bulb positioned within the reflector; and

Fig. :5 is a diagrammatic view in oblique projection.

Thej'reflector is indicated, as an entirety, by thenumeral 5. Suitably supported with in the reflector is an electric light bulb 6 which, as shown, is a two-filament bulb having one axial filament, the hot spot of which is at a and having a vertically offset fila ment, the hot spot of which is at F). The reflector 5 is formed with an axial. passage 7 through which the shank of the bulb 6 is passed to a suitable socket or support, not shown. In all radial planes, the reflector preferably has a h perbolic curve with a common axis throug the point a, and which axis is coincident with line-.y y, the axis of the reflector. The said axis g i also, is the axis of the bulb.

The preferred form of the reflector may be best made clear by assuming that it is generated by revolving the hyperbolic curve, represented by its radial section and having its focal center at a, on the axis 1 -y, while constantly changing the position of both extremities thereof, in respect to the said axis and focal center, so that the said curve will have itsmaximum length when in its lowermost position and will have its minimum length when in its uppermost position, Stated in another way, under its first half revolution, for example, fromits upper vertical position, on the axis yy, said hyperbolic curve, at its outer portion, will move farther and farther radially away from the said axis, and at its inner extremity, will move farther and farther backward from the focal point a The same fact may be expressed in still another way, by stating that, as the hyperbole is revolved downwardly on said axis y-y, (the axis of the hyper iola) it not only continuously increases its radial distance from said axis, but, at the same time, continuously shifts rearward its vertex or point of intersection with said axis, and thereby continuously increases the 'distance from said light source and focal center a of said vertex or point of intersection with said axis.

Under its secgnd half revolution, the outer portion of said curve will move nearer and nearer to said axis and its inner extremity will move forward nearer and nearer to the focal center a, until the said curve again assumes its original position; or, otherwise stated, the surface of said reflector may be assumed to be generated by a conic revolved downwardly in opposite directions, on the approximately horizontal axis of the conic, while continuously increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis. This produces a reflector, the rim or outer portion of which ma be round crapproximatelv round, and tie reflecting surface of which will be without offsets or broken surfaces, but in which the upper portion of the reflector will be much closer to the focal center a than will the lower por tion of said reflector. In a horizontal sci-- tion, the reflector is preferably bisymmetrical, as shown in Fig. 4.

As preferably constructed, all radial sec tions of the reflector have a common focal center at a, and hence, are slightly different hyperbolic curves of a different focal length.

Referring now to Fig. 5. it should be noted that the vertical axial section of the reflector consists of the two curves 2-i1; and a2. The said curve 2-50 is the assumed initial position of the generating curve, and the curve w"2 is the assumed terminal position of the said generating curve: and here it should be noted that. during the semi-revolution from top to bottom, the vertcx or point of intersection of the generating curve with the axis y, continuously moves rearward from the most forwari'i point or to the most rearward point The curve of the horizontal axial section of the reflector is represented by the line 4--w-l; and here it will be noted that the vertex or point of intersection of said curve with axis 1 1 at .1, is between the above noted points or and The generating curve of the oblique axial section of the reflector, on the line 33, is re )resentcd by the lines 3-.rand a*3.

Iere it may be further stated that the generating curves 2*? and {U52 are the curves illustrated in Fig. 2; that the generating curve [.r:'*-4 is the curve represented in Fig. at; and that the curves 3a: and :W-B are the curves represented in Fig. The generating curves 3'w and -.ii-3 are curves that correspond, respectively, to the curves and w 3 of Fig. 5, taken on the opposite diagonal plane from section Fig. 5 also clearly illustrates the already stated fact that the conic or hyperbolic curve. in revolving from its assumed initial or uppermost position 2-00 to its terminal or lowermost position 2-w, continuously increases, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, and successively passes through the upper oblique, horizontal, and lower oblique positions, diagrammatically shown in Fig. 5; and this statement is true, regardless of, in which direction the said generating curve is downwardly revolved on said axis.

The reflector illustrated in the drawings has, as above stated possible, a circular rim; and in Fig. 5, the center of the circle of this rim is indicated at 0, and, of course, is below the axis y i It follows from statements already made, and from the illustra tions in Fig. 5, and aiso in Figs. 2, 3 and 4, that the axis g 3 is the common axis of all of the conics. The common focal center a is also clearly illustrated in Fig. 5. Fig. 1 also shows that the axis of the conics revolution is located above the center of the possible circular cross section of the generated surface, which, in this instance, is shown as being at the rim perpendicular to said axis. 4

From the foregoing description, it will be seen that, in the reflector illustrated, two progressions or variations are involved in the generation of the surface, to wit: one varying the distance between the focus and the yertcx, and the other increasing the radial distance from the axis of revolution as the conic revolves from its uppermost to its lowern'iost position. The first named progression affects the spread of the beam of light, and the second named progression 'metrical, in respect to both the horizontal and vertical planes through the axis of revolution, due to the fact that the distance from the focus to the vertex is .changed by said progression of the vertex. The rate of this progression of the vertex of the conic can be predetermined for any desired specific'form of reflector and this predetermination will fix the extent of the radial progression, assuming the eccentricity of the conic to be constant. In the illustrated in stances, the rate of the rearward progression of the vertex of the conic has been predetermined by the extent to which the axis of its revolution is offset above the center of a circle, shown, in this instance, to wit: in Figs. 1 and 5 of the drawings, as located at the rim of the reflector.

The form of the reflector, illustrated in the drawings, may be algebraically expressed by the following formula stated in rectangular cartesian coordinates in terms of X and Y.

The origin is the focus a, as shown in Figs. 2, 3, 4 and 5 of the drawings.

The principal axis of the generating conic is taken as the X-axis, this being the line y-y, shown in said Figs. 2, 3, 4 and 5 of the drawings.

In the formula, d is the distance from the focus to the vertical plane of a circle, assumed, in this instance, to be located at the rim of a reflector, as best shown in Figs. 1 and 5 of the drawings. Said distance d is measured on the axis of the conic.

In the formula, 7' is the radius of said circle.

In the formuia, Fa represents the perpendicular distance from the center of said circle to the axis of the conic.

Said elements 0!, 'r' and k are arbitrary constants, predetermined by the designer.

In the formula, e denotes the eccentricity of the generating conic, which, in the in- Stance illustrated in the drawings, is a hyperbola.

In the formula. 0 denotes the angle between the vertii'wal plane through the axis of the conic and any radial plane through said axis.

In the fornuila, g denotes the ordinate of the hyperbola at the distance d from the focus in any one of the planes through the axis of the conic. For example, in the illus tratcd form, it denotes the distance from the point at which the axis of the conic inter sects the plane of the circle, assumed to be located at the rim of the reflector, to any po nt on the clrcumferenceof said circle, and which distance 9 1s derived or can be computed by the following equation:

g il: cos {r is sin fi The equation of any axial section of the reflector in a plane through the axis making an angle ll with the vertical plane through the axis 18 aw/m described, may be made in a great many different ways. For instance, they ma be pressed or cast against a pattern or form made with the proper outlines of the reflect ing surface. The form or die, itself, may also be made in a great many different ways. One very feasible way of making the same would be as follows:

Take, for example, 180 rectangular plates, wedge-shaped in cross section, the op osite lateral faces of which have each a (liverg ence from each other of 2 degrees, the plates being ofsufficient area to permit the corresponding 181) radial section curves to be plotted thereon. Then on one face of each plate, plot out'the curve, in accordance with the above formula, using the sharp edge of the wedge as the axis of the reflector. Then, saw or cut or file these wed eshaped plates on the lines of the plotte curves. Then assemble together all of the wedge-shaped plates to form a solid mass. This will give a solid body with portions of the thick outer edges of the plates projecting outward slightly beyond the plotted curves. 'lhen, carefully file away the said projecting portions until the solid surface is reduced to a smooth exterior on the lines of the plotted curves. This, when the wedge plates are properly secured together, by welding, or otherwise, will give a complete solid form or die on which the reflectors may be pressed or cast. i

The peculiar contour of the above dcl (d i \/cl +q 2 1) scribed reflector will necessarily distribute the reflected light in a manner radically dif' ferent from the distribution secured from an ordinary reflector, wherein the surface is simply one of revolution, regardless of which one of the three conics, ellipse, parabola. or hyperbole, may be used. ln'a'll of such ordinary reflectors, as is well known, the surface normals are in radial planes and in tersect the axis of revolution, and, conscquently, the incident ray, the surface normal and the reflected ray are in one and the same radial plane; and the general result is that there will be an equal amount of light above and below the horizontal plane of thc axis of the reflector, when the light is lo cated at the focus.

The peculiar contour of this new reflector, above described, will have an entirely different effect in-the distribution of the light, for the controlling reason that the surface normals are necessarily out of and below the radia planes of the incident rays. and hence, it necessarily follows that all of the incident rays, which strike any portion of the reflector above the horizontal plane of its axis will be deflected downward. The angle of incidence and the angle of reflection are, of course, the same, being equally in clined to the surface normal, but will wary for different rays, depending on thc position of the respective points at which the incident ray strikes the said surface of the said reflector; and a large number of said incident rays will be so deflected downward, at such a degree, that the reflected rays will reach the ground, and will cooperate with the rays reflected from that portion of the reflector below the horizontal planc of the axis to produce the desired illuminatin; effect. The same principles, in respect to surface normals and in respect to the deflection, of course. apply to that portion of the rcflector below the plane of its horizontal axis, and hence, all reflected rays therefrom are deflected downward to a greater degree and reflector above its horizontal axis, will not be deflected downward to such a degree as to pass below the horizontal plane of the axis of the reflector, and will cooperate with the unreflectcd rays from the light to afford all of the light needed above the horizontal plane of the axis of the reflector.

Of course, it further follows, from the above stated facts, that objectionable glare and blinding effects a re practically eliminated. Most of the light is thrown downward and reaches the ground, and hence, there is no strong glaring beam to strike the face of an approaching driver or pedestrian.

Of course, it will be understood, that, while the drawings illustrate a reflector embodying my invr ntion in what is its prefcrrcd form, so far as 1 now know, and that while the specific description is directed to this specific form, it must. nevertheless, be understood that this specific form was selected for illustrative purposes only, as required by the law, and that I do not limit myself to that specific illustrated form. The design of the structure depends upon several variable factors, as hitherto made clear in several different ways; and, of course, any change in any of these variable factors will, to some extent, vary the resulting shrface generated, without departure from the invention; and, in the accompanying claims, I desire to cover and protect my invention in the broadest way possible.

hat I claim is:

1. A headlight set for approximately hori zontal projection and comprising a reflector and a light source therein, said reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing the distance from said light source of its vertex or point of intersection with said axis.

2. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, said reflector having s surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis.

El. headlight set forapproximately horizontal projection and comprising a reflector and a light source therein. a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing the distance from said light. source of its vertex or point of intersection with said axis, and the vertices or points of intersection with sajl axis of the curves of the lower portion of the reflector being at greater distances from said light source than the vcrticcs or points of intersection with said axis of the curves of the upper portion of the reflector.

l. A headlight set for approximately horizontal projection and comprising areflector and a light source therein, a material portion of the reflector having a surface substantially corresponding to a surface gener atcd by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing the distance from said light source of its vertex or point of intersection with said axis, and the radial distances from said axis of the curves of the lower portion of the reflector being greater than the radial distances from said axis of the curves of the upper portion of the re llector.

I. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein. a material portion of the reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasin at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, and the vertices or points of intersection with said axis of the curves of the lower portion of the reflector being at greater distances from said light source than the vertices or points of intersection with said axis of the curves of the upper portion of the reflector.

6. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, a material portion of the reflector having a. surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while increasing, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, and the radial distances from said axis of the curves of the lower portion of the reflector being greater than the radial distances from said axis of the curves of the upper portion of the reflector.

7. A headlight set for approximatelyhori- ,zontal pro'ection and comprisinga reflector and! a lig t source therein, said reflector having a surface substantially corresponding to a surface generated by a conic revolved in a downward direction on the approximately horizontal axis of the conic while vary1ng, at the same time, both its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis, and the radial distances from said axis of the conics of the terminal portions of the surface thus'generated bein greater than the radial distances from sai axis of the oonics of the initial portions of the surface thus generated.

8. A headlight set for approximately horizont'al pro 'ect1on and comprising a reflector and a lig t source therein, said reflector having a surface substantially correspondin to a surface generated by a conicrevo ved. in a downward direction on the approximately horizontal axis of the conic while vary ng the distance from said light source of its vertex or point of intersection with said axis, and the vertices or points-of intersection with said axis of the conics of an the, terminal portions of the surface thus generated being at greater distances froin'- 7 said light source than the vertices or points of intersection with said axis of the comes of the initial portions of the surface thus '35 generated.

9. A headlight set for approximately horizontal projection and comprising a reflector and a light source therein, said reflector having its entire surface substantially correspondin to a surface generated by a conic revolve downwardly, in oppositedirecti'ons, on the approximately horizontal axis of the donic while continuously increasing the distancefrom said light source of its vertex or pointof intersection with said. axis.

10. A- headlight set for approximately horizontal projection and comprising a re- Hector and a light source therein, said reflector having its entire surface substantially.

corresponding to a surface generated by a conic revolved downwardly, in opposite directions, on the approximately horizontal axis of the conic while continuously increasing, at the same time, both' its radial distance from said axis and the distance from said light source of its vertex or point of intersection with said axis.

11. A headlight set for. approximately horizontal projection and comprising. a re- .flector and a light source therein, the surface of said reflector substantially.-correspondin to a surface generated by a conic revolve downwardly, on the approximately horizontal axis of the conic while continuously increasing its radial distance from said axis, and the vertices or points of intersection with-said axis of the conios of the lower portion of the reflector thus generated being at greater distances from said light source COI'I'QEUOHS in Letters Patent No. 1345056 It is hereby certified that in Letters Patent No. 1,345,056, granted June 29, 1920, uptm the application of Ovcrton Winstoh, of Minneapolis, Minnespta, 1 01- an imjjt'otr m eiit in HeadIighL," errors appear in the printed specification r etquiring corrqction as follows: Page 2, lines 97-98, for the word instances read i nstrmce; pagfi; line 18, equati onfaftcr the lcttg r. "(1 insert the sign of equality find that th said Letters Patnt should be read with these corrections t'hqarein that the same may ponform to the record of the case in the. Patent Oflice. I

November, A. D., 1920.

L. B. MANN,

Acting Cmnm-isaianer of Patents.

Signed and saled this 30th dhy of [any] 

